Summary: Boe Prox shows how you can find certificates that are expiring.
How can I find if I have any certificates on my system that are expiring within 30 days?
Use the ExpiringInDays dynamic parameter when working with the certificate provider, for example:
Get-ChildItem Cert:\LocalMachine\My\ -ExpiringInDays 30 |
Select-Object Thumbprint, Subject, NotAfter